The Active Crossover Designer is a tool for designing active and DSP loudspeaker crossovers. The tools are implemented as spreadsheets for Microsoft Excel (version 2003 or later) and Open Office Calc (version 3.3 or later), are free, and are designed for the serious hobbyist. There is a crossover design example for a 2-way loudspeaker provided as a tutorial, and a comprehensive technical manual is included.

The ACD and ACD-L tools can model up to 4-way loudspeakers. Models are assembled from driver and system templates. The user can then import driver response measurements, determine acoustic offsets for precise phase determinations, and then develop crossovers comprised of any number of cascaded first and second order filters to build higher order crossovers.

With ACD, the crossover can be implemented using one of the MiniDSP digital crossover products with the advanced biquad programming feature. With ACD-L the crossover is implemented in software using the linux audio program ecasound with the filters implemented as LADSPA plugins. ACD includes analog filter transfter functions if an analog active realization of the filters is desired.

The conceptual approach for these tools has been to create an "open" platform using commonly available spreadsheet tools that many DIY hobbyists are familiar with. Because all of the calculations are done using spreadsheet formulas that are all visible and accessible, the tools are fully extensible. The user can change any and everything, or add on new functionality, plots, and so on. Some examples of useful add-ons for the CORE TOOLS are provided in the EXTENSIONS section.

The tools are distributed as Excel (XLS) files, however, these are 100% compatible with Open Office Calc.

The Active Crossover Designer consists of the CORE TOOLS and EXTENSIONS.

EXTENSIONS:

As mentioned above, the CORE TOOLS can be augmented with EXTENSIONS that provide additional information and capabilities. As new extensions becomes available, they wil be posted in this section.

1. TWO-DRIVER PHASE TRACKING

The two driver phase tracking extension provides a plot of the phase angle for each of two drivers as well as a plot of the relative phase angle. See screen shot at right. This information is extremely useful for monitoring the phase behavior around the crossover point. Because of the way the core ACD tools are designed, this functionality can only be provided as an extension. For more than two drivers, use multiple versions of this spreadsheet in your project.

Follow the set-up instuctions provided in the spreadsheet.

Thanks to Sasha Jovanovich for the concept and an early version of this extension!

The File Import-Export Helper is an Excel only spreadsheet that makes it easy to import/export FRD files to/from ACD and other software written by the author. The interface allows the selection of column separator, and performs various housekeeping functions while allowing the user to employ the familiar File Open dialog using operating system calls. This extension uses VBA macros - if prompted, please enable macros when opening the file.